The presence of complex mixtures of compounds in ambient air, many of which are either unknown or uncharacterised makes an assessment of risk associated with these exposures problematic. Bioanalytical methods can provide an integrative assessment of complex mixture potency for specific mechanisms of toxicity within these contexts. The aim of this study was to evaluate the suitability of monitoring ambient air exposures as sampled by (polyurethane foam) PUF passive air samplers (PAS) using effect based techniques (bioanalytical methods). Passive samplers have the advantage of offering a low-tech inexpensive monitoring strategy which can thereby increase sampling capacity across a broader range of scenarios simultaneously. One challenge posed by the application of passive samplers in particular for these assessments has been the expression of potency estimates in relatively non-comparable terms specific to a given dose of the sampler or for a specific deployment period. The project was therefore designed in order to address these aims and previously identified challenges by investigating the applicability of these techniques for: monitoring in both indoor and outdoor air, the determination of seasonal exposure gradients; the determination of exposure gradients in different locations (urban capitals, regional centres, background); and the application of in-situ calibration to provide comparable effect measurements in terms of equivalent reference compound air concentrations. Air sampled using PUF PAS was monitored for its capacity to induce biological responses which are mechanistically relevant to critical health endpoints in these scenarios. The mechanisms assessed included genotoxicity (DNA damage – umuC assay), Aryl hydrocarbon receptor (AhR) activity (CAFLUX assay), and estrogenicity (ESCREEN assay). The findings from this effect based monitoring revealed that the level of biological response measured changes with the exposure scenario (indoor vs. outdoor; summer vs. winter; urban capital cities vs. background locations). Estrogenicity for example assessed as estradiol equivalent air concentrations (E Eq BIO) averaged 54 pg.m-3 (1.5 - 185 pg.m-3) in indoor air, while samples from ambient air were found to be not estrogenic. Total aryl hydrocarbon receptor (AhR) activity assessed as 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalent air concentrations (TCDD Eq BIO) averaged 4.1 pg.m-3 (1.3 – 7.2 pg.m-3) in indoor air while samples from ambient air averaged 15 pg.m-3 (1.5 – 46 pg.m-3)in summer and 53 pg.m-3 (2.2 – 251 pg.m-3) in winter. The relationship for both direct (-S9) and indirect (+S9) acting genotoxicity and AhR activity were found to be relatively consistent with respect to both season (elevated in winter) and location (elevated in urban capital cities). Overall suitable techniques were developed for combining passive sampling with multiple end-point toxicity testing and it was demonstrated that these techniques may be applied across different exposure scenarios. During the course of this method development and interpretation process a range of limitations were identified relating to: the use and application of effect based techniques to monitor environmental samples; the use of passive samplers within this context specifically; and also with the application of in-situ calibration techniques to passive samplers to improve the comparability of these assessments.